Figure 2

Loss of NMDA-receptor independent LTP in the mossy fibre pathway of Tg2576 mice. A) An example LTP experiment in a 25 month old WT mouse. After a 10 minute period of stable baseline EPSPs in response to low frequency stimulation (0.05 Hz), a conditioning stimulus consisting of 3, 1 s, 100 Hz train was applied at the time indicated by the arrow. Post conditioning low frequency stimulation-evoked EPSPs were followed for another 30 minutes after which time the synaptic depression produced by DCG-IV (2 μM) application was determined. The inset show example traces recorded just prior to the conditioning stimulus and just prior to DCG-IV application. B) An example recording similar to that in (A) but from a Tg2576 mouse. C) Pooled LTP data from 7 WT and 6 Tg2576 slices (taken from 4 and 5 animals, respectively). Note the LTP in slices prepared from Tg2576 mice does not persist. DCG-IV consistently depressed the synaptic responses by ~80% in both groups.